It has heretofore been proposed to provide an instrument for performing a tracheotomy, the instrument comprising a tube, or cannula, of arcuate configuration and an incisor assembly fitting within the tube. The incisor assembly has comprised a handle, or knob, at the outer end of the tube, a head having a cutting blade projecting from the inner end of the tube and a rod connecting the knob to the cutting head.
Exemplary of such devices are the instruments disclosed in U.S. Pat. No. 2,873,742 to Sheldon of Feb. 17, 1959; U.S. Pat. No. 2,865,374 to Brown of Dec. 23, 1958; and U.S. Pat. No. 3,384,987 to Brummelkamp of Mar. 21, 1968.
The use of sharp cutting blades at the inner end of a tracheal tube in order to make, or enlarge, an incision as the tube is inserted, has been found to have serious disadvantages because the sharp point, or blades, inserted in the front of the trachea may perforate, or damage, the opposite side of the trachea or perforate the gullet lying behind the trachea. Similarly, even more damage could occur in the use of a sharp pointed, hollow needle of hard metal for making the initial incision into the trachea and then withdrawal of the needle for further insertion of the hard cutting edge tip of a trocar, as taught in the Brummelkamp patent. Such instruments are believed to no longer be accepted in modern surgical practice and have become obsolete in favor of tracheal tubes and obturators of soft plastic, inserted, after the incision has been made, by a suitable tracheal spreader.
It has also been proposed to provide a tracheal tube, or guide conduit with an inner expander element telescopically arranged therein for enlarging the incision in the neck. The element having a ball at the tip for attachment of a hollow tubular leader. Such an apparatus is disclosed in U.S. Pat. No. 3,511,243 to Toy on May 12, 1970.
Apparatus for sealing the oesophagus and providing artifical respiration is disclosed in U.S. Pat. No. 3,683,908 to Tantrimudalige et al on Aug. 15, 1972 wherein a curved tube with a cuff is introduced through the mouth, there being a small bore, stomach washing tube extending along the main tube with the outer end connected to a supply of washing water.
None of the above patents disclose a tracheotomy tube with an obturator removably positioned therewithin, the obturator having a valve plug affixed by s strap to a valve cap, and made of relatively soft material free of sharp cutting edges or sharp guide tips and which is provided with air passages permitting the patient to breathe while the device is inserted into the trachea.